Can I conditionally hide a route (e.g. action / local task)

Question

Consider an action button on a custom entity's canonical page:

mymodule.actions.yml:

entity.item.action:
  route_name: entity.item.action
  title: 'Do something'
  appears_on:
    - entity.item.canonical

mymodule.routing.yml:

entity.item.action:
  path: '/item/{item}/action'
  defaults:
    _controller: '\Drupal\mymodule\Controller\ItemController::action'
    _title: 'Do something'
  requirements:
    _permission: 'edit items'

I would like to show or hide the action button depending on the value of some field of the entity.

How could I achieve this? Would it be wise to add custom access checking for this?

Answer 1

You can add a custom access method on your controller. According to this page you should have access to your item argument in the access method so you should be able to restrict access based on a value on that item. The action should be hidden if the user does not have access to the route, i.e. your custom access method denies access.

Answer 2

I was doing a similar task with hook_menu_local_tasks_alter. Keep in mind though that you will have to query for the current entity (e.g. node) separately as it is not passed into this hook as a parameter

Something like this:

function XXX_menu_local_tasks_alter(&$data, $route_name) {
  $routes = ['entity.node.canonical'];

  if (in_array($route_name, $routes)) {
    foreach ($data['tabs'][0] as $task_name => &$task_array) {
      if ($task_name == 'entity.node.canonical') {

        $node = \Drupal::routeMatch()->getParameter('node');
        if ($node instanceof \Drupal\node\NodeInterface) {

Answer 3

Two useful approaches are outlined in the Drupal 8 guide / Providing module defined actions. These are:

1. Derivers that dynamically generate one or multiple actions
2. Custom classes for the actions

I nearly solved the issue with approach 1. However, I'm still struggling with caching. This is my solution so far:

namespace Drupal\mymodule\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\mymodule\Entity\ItemInterface;
use Drupal\mymodule\Entity\Item;

/**
* Defines dynamic actions.
*/
class ItemLocalActions extends DeriverBase {

 /**
  * {@inheritdoc}
  */
 public function getDerivativeDefinitions($base_plugin_definition) {
   // Implement dynamic logic to provide values for the same keys as in example.links.task.yml.
   $id = \Drupal::routeMatch()->getRawParameter('item');
   $item = Item::load($id);

   if ($item instanceof ItemInterface) {
     switch($item->getStatus()) {
       case ItemInterface::STATUS_NEW:
         $this->derivatives['entity.item.action'] = $base_plugin_definition;
         $this->derivatives['entity.item.action']['title'] = t('Do something');
         $this->derivatives['entity.item.action']['route_name'] = 'entity.item.action';
         break;

         // add more derivative definitions here, depending on the item's state
     }
   }
   return $this->derivatives;
 }
}

and in mymodule.links.action.yml:

entity.item.state_actions:
  deriver: '\Drupal\mymodule\Plugin\Derivative\ItemLocalActions'
  cache_tags:
    - item_list
  appears_on:
    - entity.item.canonical

As stated above, caching is still a problem. Even though I set the appropriate cache tags, the actions are still rendered from cache.

Related questions:

• Clearing local tasks cache